Studies have conventionally been made of a power storing apparatus for storing electric power by a form of kinetic energy.
Such a power storing apparatus is composed of a rotor having flywheels around the rotary shaft, a stator provided with a coil for supplying a driving power for rotating the rotor and taking out the induction electromotive force generated by the rotation of the rotor, a bearing means for rotatably supporting the rotary shaft of the rotor, and a casing accommodating the stator, the bearing and the rotor. This type of conventional power storing apparatus has a low earthquake resistance, because it is designed without leaving a surplus strength in order to reduce the friction loss of the bearing. Especially, in a bearing employing the pinning effect of a type II superconductor, rigidity is subject to a gradient of a magnetic field and therefore low. For example, it is rocked about 1 to 2 mm due to a burden corresponding to the weight of a rotor. In order to prevent the elements of the power storing apparatus from scattering at the time of an accident, the apparatus is often accommodated in a firm container.
There has also been an attempt at supporting the casing on the ground by an elastic member having a low spring constant in order to prevent vibration, which is caused by an earthquake or the like and which may dislocate the rotor, from being transmitted from the ground to the casing.